(a) Field of the Invention
The present invention relates to an object-based three-dimensional audio system, and a method of controlling the same. More particularly, the present invention relates to an object-based three-dimensional audio system and a method of controlling the same that can maximize audio information transmission, enhance the realism of sound reproduction, and provide services personalized by interaction with users.
(b) Description of the Related Art
Recently, remarkable research and development has been devoted to three-dimensional (hereinafter referred to as 3-D) audio technologies for personal computers. Various sound cards, multi-media loudspeakers, video games, audio software, compact disk read-only memory (CD-ROM), etc. with 3-D functions are on the market.
In addition, a new technology, acoustic environment modeling, has been created by grafting various effects such as reverberation onto the basic 3-D audio technology for simulation of natural audio scenes.
A conventional digital audio spatializing system incorporates accurate synthesis of 3-D audio spatialization cues responsive to a desired simulated location and/or velocity of one or more emitters relative to a sound receiver. This synthesis may also simulate the location of one or more reflective surfaces in the receiver's simulated acoustic environment.
Such a conventional digital audio spatializing system has been disclosed in U.S. Pat. No. 5,943,427, entitled “Method and apparatus for three-dimensional audio spatialization”.
In the U.S. '427 patent, 3-D sound emitters output from a digital sound generation system of a computer is synthesized and then spatialized in a digital audio system to produce the impression of spatially distributed sound sources in a given space. Such an impression allows a user to have the realism of sound reproduction in a given space, particularly in a virtual reality game.
However, since the system of the U.S. '427 patent permits a user to listen to the synthesized sound with the virtual realism, it cannot transmit the real audio contents three-dimensionally on the basis of objects, and interaction with a user is impossible. That is, a user may only listen to the sound.
In addition, with respect to U.S. Pat. No. 6,078,669 entitled “Audio spatial localization apparatus and methods,” audio spatial localization is accomplished by utilizing input parameters representing the physical and geometrical aspects of a sound source to modify a monophonic representation of the sound or voice and generate a stereo signal which simulates the acoustical effect of the localized sound. The input parameters include location and velocity, and may also include directivity, reverberation, and other aspects. These input parameters are used to generate control parameters that control voice processing.
According to such a conventional computer sound technique, sounds are divided by objects for ‘virtual reality’ game contents, and a parametric method is employed to process 3-D information and space information so that a virtual space may be produced and interaction with a user is possible. Since all the objects are separately processed, the above conventional technique is applicable to a small amount of synthesized object sounds, and the space information has to be simplified.
However, in order to utilize natural 3-D audio services, the number of object sounds increases, and the space information requires a lot of information for reality.
With respect to Moving Picture Experts Group (MPEG), moving pictures and sounds are encoded on the basis of objects, and additional scene information separated from the moving pictures and sounds is transmitted so that a terminal employing MPEG may provide object-based dialogic services.
However, the above conventional technique is based on virtual sound modeling of computer sounds, and, as described above, in order to apply natural 3-D audio services for broadcasting, cinema, and disc production, as well as disc reproduction, the number of sound objects becomes large, and the various means for encoding each object complicate the system architecture. In addition, the conventional virtual sound modeling architecture is too simple to effectively employ the same in a real acoustic environment.